biostudies-literatureUnknown80Peng C<h4>Background</h4>This study explores potential associations between asthma and the Systemic Immune-Inflammation Index (SII).<h4>Methods</h4>The study primarily focuses on adults with complete data on SII and asthma from the National Health and Nutrition Examination Survey database (2015-2020). SII is calculated using the formula: platelet count × neutrophil count / lymphocyte count. The connection between SII and asthma was assessed through baseline feature analysis, weighted multivariate regression, subgroup analysis, and smooth curve fitting.<h4>Results</h4>A total of 13,334 participants were included, with 2045 individuals (15.34 %) having asthma. Subgroup analysis and interaction tests revealed no significant impact of gender, age, body mass index, vitamin C, magnesium, coronary hearClinics (Sao Paulo, Brazil)100779https://www.ebi.ac.uk/biostudies/studies/S-EPMC12450745biostudies-literatureThe hidden connection: systemic immune-inflammation index and its role in asthma.PMC12450745Peng CWang TGao DZhou ZfalseThe hidden connection: systemic immune-inflammation index and its role in asthma.<h4>Background</h4>This study explores potential associations between asthma and the Systemic Immune-Inflammation Index (SII).<h4>Methods</h4>The study primarily focuses on adults with complete data on SII and asthma from the National Health and Nutrition Examination Survey database (2015-2020). SII is calculated using the formula: platelet count × neutrophil count / lymphocyte count. The connection between SII and asthma was assessed through baseline feature analysis, weighted multivariate regression, subgroup analysis, and smooth curve fitting.<h4>Results</h4>A total of 13,334 participants were included, with 2045 individuals (15.34 %) having asthma. Subgroup analysis and interaction tests revealed no significant impact of gender, age, body mass index, vitamin C, magnesium, coronary hear2025-01-01T00:00:00Z2025 Sep2026-06-03T17:20:03.29Z2026-04-29T03:13:13.021ZS-EPMC124507454091518010.1016/j.clinsp.2025.100779